1. Field of the Invention
The present invention relates to a touch panel stackup. More specifically, the invention relates to the touch panel stackup integrally formed on a singular substrate.
2. Description of Related Art
Touch panels are popular input devices. When the user touches a certain position on the touch panel, corresponding to the text or the images on the underneath display device, the touch panel senses the tactile signals and transmits them to a controller for further signal processing. The controller processes the tactile signals and outputs signals corresponding to the touched position. There are several types of touch panels, for example, resistive types, capacitive types, infrared types, surface acoustic wave types, etc. For instance, the capacitive touch panels detect the difference of capacitance of the touch panel. When the user touches the touch panel, the capacitance on the corresponding position is changed. The touch panel and the controller detect and calculate the difference in capacitance and then output corresponding signals.
The conventional touch panel includes one or more layers of sensing electrodes, conductive circuits, masking elements, a supporting substrate, and a protective lens substrate providing anti-scratch, anti-glare, and/or anti-reflective function. In the fabricating process of conventional touch panels, the components are formed separately on the supporting substrate and the protective lens substrate. Afterwards, the supporting substrate and the protective lens substrate are laminated to form the touch panel. For example, the sensing electrodes are formed on the supporting substrate, and the masking elements and the conductive circuits are formed on the protective lens substrate. After laminating the supporting substrate and the protective lens substrate, the conductive circuits are electrically coupled with the sensing electrodes for transmitting tactile inputs. The masking elements can cover the conductive circuits to eliminate the visual interference of the conductive circuit when the users watch the information on the display. The conventional two-substrate approaches increase the thickness of the touch panels. Moreover, a precise positioning is needed in the lamination process to properly connect the sensing electrodes and the conductive circuits. The manufacturing complexity is therefore increased.